Analysis of the swallowing process in humans has been performed for the last couple of decades, with the purpose of detecting abnormalities which may be the cause of notable pathologies and infections, e.g. if inhalation occurs during the swallowing process, there is the risk of material entering inside the respiratory tract and it may cause pulmonary infections. In the same way, disturbances may occur in the efficiency of transporting the bolus, which may lead to malnutrition. Abnormal swallowing receives the name dysphagia.
The swallowing process is generally studied by exposing a patient to x-rays whilst he/she is made to swallow a radiographic contrast substance. Simultaneously, the process is recorded by a video camera so that the doctor can analyse the movement of said oropharyngeal structures involved in said process. This type of diagnostic procedure is called a videofluoroscopic swallow study or MBS (modified barium swallow).
Specifically, it has been determined that the forwards and upwards movement of the hyoid bone and the upwards movement of the larynx, are two important elements in the cricopharyngeal region opening process and in the laryngeal vestibule closure process.
The problem with the means currently used to analyse the swallowing process is that they do not permit a real-time diagnosis to be obtained, due to the fact that, for a verdict to be given, the doctor should view the same swallowing event several times to determine at what point in the section or path of the material or liquid the anomaly or dysphagia occurs. Furthermore, said study is currently qualitative, which in many occasions makes it difficult to determine the degree or level of dysfunction. Since all the events of the swallowing act occur in under a second, many of the dysfunctions of patients with dysphagia are revealed in time intervals which cannot be seen by the human eye when they are observed at the rate at which they normally occur.
In an attempt to quantify the swallowing process, in “Interactive Computer Program for Biomechanical Analysis of Videoradiographic Studies of Swallowing” (AJR 153:277-280, 1989), Logemann et al. disclose a computer program to digitize frozen images and represent the position of anatomic structures in the oral and pharyngeal cavities therein. To do this, they digitize frozen images recorded on video; they identify several anatomical reference points in each image; they then identify anatomical points of interest; and via the computer program or software medium, they calculate the spatial coordinates of said anatomical points of interest in each one of the previously digitized images. This software provides quantitative information on the position of the structures which can then be processed to produce time-dependent arrangement graphics of said structures. The doctor first selects the individual images which he/she wants to digitize, next, the programs analyse them in the order pre-established by the user. In any case, quantitative analysis using this method takes a long time, information is lost, as the method only permits the analysis of spatial and not temporal events; and the image-to-image analysis does not allow the process to be viewed in real time.
From the state of the art, we can deduce the need for a system to study and analyse the swallowing process which permits making a real-time analysis with greater precision. The present invention provides numerous advantages with respect to the procedures and equipment or systems for the analysis of swallowing in humans, while resolving the previously posed problems.